A liquid crystal display has a liquid crystal cell and a polarizing plate. The polarizing plate, which generally has a protective film made of cellulose acetate and a polarizing film, can be obtained by, for example, dyeing a polarizing film made of polyvinyl alcohol with iodine, stretching the same and layering protective films on both faces thereof. In a transmission type liquid crystal display, polarizing plates are attached to both sides of a liquid crystal cell and one or more optically compensatory films are further provided in some cases. In a reflection type liquid crystal display, a reflecting plate, a liquid crystal cell, one or more optically compensatory films and a polarizing plate are usually provided in this order. A liquid crystal cell comprises liquid crystal molecules, two substrates in which the liquid crystal molecules are enclosed and an electrode layer for applying voltage to the liquid crystal molecules. Concerning liquid crystal cells, there have been proposed display modes by which ON/OFF switching is made depending on the orientation state of liquid crystal molecules and which are applicable both of the transmission and reflection types, for example, TN (twisted nematic), IPS (in-plane switching), OCB (optically compensatory bend), VA (vertically aligned) and ECB (electrically controlled birefringence) modes.
Among these LCDs, 90° nematic mode liquid crystal displays (hereinafter referred to as the TN mode), which are driven by a thin-film transistor with the use of nematic liquid crystal molecules having a positive dielectric anisotropy, have been mainly employed when excellent visual qualities are needed. However, the TN mode has such a viewing angle characteristics that although excellent display characteristics are achieved when viewed from the front, the contrast is lowered and inverted gradation (reversion in brightness), etc. arise in gradient display when viewed from an oblique direction, thereby worsening the display characteristics. Thus, it has been strongly required to overcome this issue.
On the other hand, the share of wide-viewing angle liquid crystal modes such as the IPS mode, the OCB mode and the VA mode has been expanding with the recent increase in the demand for liquid crystal television sets. Although the visual qualities have been improved year after year in each of these modes (JP-A-9-211444, JP-A-11-316378, JP-A-2-176625, JP-A-11-95208, JP-A-2003-15134, JP-A-11-95208, JP-A-2002-221622, JP-A-9-80424, JP-A-10-54982, JP-A-11-202323, JP-A-9-292522, JP-A-11-133408, JP-A-11-305217 and JP-A-10-307291), color shift in viewing from an oblique direction still remains unsolved.
On the other hand, there has been reported a method of improving color shift in the VA mode by using a phase contrast film with the use of a birefringent layer consisting of two layers made of different amorphous polymer materials (JP-A-2005-77853). However, this method can be hardly applicable to the OCB mode and the IPS mode. Moreover, a highly complicated procedure is required in producing this film.